Transcript

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DR BENJAMIN: So I was going to talk to you about football. But Tuoc says we should talk about something to do with cataracts. So we’re gonna talk about cataract surgery in difficult eyes. And these are the objectives. Really to appreciate that planning is needed for managing complex cases. And then we’ll show a number of complex cases, and really to make the point that complexity is just simplicity multiplied. You can break it down into lots of simple steps. And then just to demonstrate that you need to be adaptable to cope with more complex cases. Now, these are your multiple choice questions, and they may not seem relevant at the moment. The first one is: What advantages can data capture give when performing surgery? The second one is: I want you to suggest two strategies for shallow anterior chambers in cataract surgery. The third one you should be able to answer now. What agent should be used to identify vitreous in a complex case? Anybody know? Well done. You passed. Okay. So the first thing is: We’re gonna talk about how you can prevent or anticipate complications. And this slide just shows the cataract surgery rates in the UK from 1963 to 2003. And there are two interesting things to note. The first is that I started ophthalmology in 1983. I started training in ophthalmology in 1983. I know I look too young. And the other thing to notice is that I became a consultant in 1990. And look what happened to the cataract rate after that! So it’s the commonest operation we do in the National Health Service in the UK. It’s the commonest operation performed in the United Kingdom. So it’s about 4.5% of all operations performed in the UK. Local anesthetic in 95%. And phacoemulsification in 99.7%. And where we differ from most of the world is that trainees performed one third of all cataract operations in the UK. And we do about 400,000 a year. 400,000 a year. A year. Now, some cataract units in the UK collect postoperative data in an electronic patient record. And a professor called Don Sparrow has analyzed the data from 55,000 cataracts. And he analyzed the complications, which are all these. So posterior capsule rupture, iris trauma — there are a whole range of complications he analyzed, and what percentage of cases they occurred in. So you can see that vitreous loss, posterior capsule rupture, vitreous loss, 1.92%. So that’s 1 in 50 of every cataract that’s performed. So what he then did — he identified the causes of those complications. He identified what caused the complications. And these were the causes of the complications of posterior capsule rupture/vitreous loss. And so if the patient is unable to lie flat, there’s an adjusted odds ratio of 1.27. It’s 1.27 times more likely you’ll lose vitreous if the patient can’t lie flat. And if the patient is male, it’s a little more likely. Males have a lot to put up with. And right at the bottom of the list — trainee surgeons. 3.73 times as likely to lose vitreous. And you would expect that. Now, what Professor Sparrow worked out is that if you multiply all the odds ratios together for a particular patient, you can work out a probability of that particular complication. So, for example, female patient, 90 years old, consultant surgeon doing the operation. You multiply all those risk factors together, and the predicted probability of vitreous loss is 1.7%. Yeah. But what if it’s a male patient, 90 years old, pseudoexfoliation, glaucoma, white cataract, no view of the fundus, small pupil? And they can’t lie flat? Then the odds ratio is 44%. So this patient is almost as likely to lose vitreous as not. So I showed you this form recently. These are the scores that we use for those adjusted odds ratios. And we can now risk-stratify the patients. So hopefully if we give the difficult cases to the more experienced surgeons, we’ll have a lower risk, a lower rate of posterior capsule rupture. So some complex cases. Now, here’s a small pupil. Who would operate on this patient? Hands up. Nobody? One? Okay. Good. And there are things you can do to make it easier. So there are some… You can put a Malyugin ring. This is a ring designed by Boris Malyugin. And suddenly the operation is much easier. You can use iris hooks. There are a number of ways of reducing the risk. And a small pupil is a definite risk. So if you can make the pupil bigger, the risk goes down. And we talked yesterday, I think, about the side port. 65% of all the fluid you lose comes out of the side port, where the second instrument is. You can see all the fluid escaping from here. It can sometimes get in the way of the view. So if you just take it out, it makes things a lot clearer. It gets in the way of the surgery. All the water. So just take the second instrument out. It makes things much easier. You’ll see in a moment, I think, the instrument comes out, and then all the water disappears. So if the view is difficult, just take the instrument out, do some more surgery, and only put the instrument back in when you need it. Now, remember that if the patient can’t lie flat, that’s an additional risk. This gentleman — it was quite difficult. So sometimes you have to stand up. You’ve got to make it comfortable to operate. This is difficult, because you have to do the phaco, and then if you want to focus the microscope, you change feet, and then the phaco again. So it’s a bit tiring, but it makes it much easier than trying to sit down. It is a useful trick to do, called the Cionni maneuver. What you’ll see as the phaco probe goes into the eye, the anterior chamber goes very deep, suddenly. Really deep. And… Sorry. So that makes it quite difficult to reach the cataract. You can’t reach, you can’t get to the cataract. And this is due to reverse pupil block. Reverse pupil block. So you… So you have to break the pupil block. And you do that by putting an instrument under the iris and just lifting it forwards. So watch. Under the iris. And lift it forwards. And the whole chamber will shallow again. And that makes the phaco much easier. But each time you put the phaco into the eye, it will happen again. So you have to do it each time. So here are some examples of difficult cases. This is a very shallow anterior chamber. The corneal wound is a little too close to the limbus. So the easiest place for the fluid to escape is under the iris, and it will push the iris out of the eye. You’ll see it’s starting to happen already. Starting to come out. And… So once you see this happening, it’s really important to stop and sort it out. And sometimes it’s very difficult, because the wound is just made in the wrong place. So you can close the wound, put a stitch in, and make another wound. And the big problem arises when you inject fluid. When you’re starting to do the hydrodissection. The iris will come straight out again. Because that’s the pathway of least resistance. The pathway of least resistance. The fluid will find the easiest path out of the eye. Once it’s happened, the pupil sphincter is damaged, and that means the iris is very floppy. So, again, it’s important to deal with it. If you can do a little iridectomy, iridotomy, to let the fluid out through there, or you can close the wound and put a stitch in and make a fresh wound. But the easiest solution is to do the capsulorrhexis through the side port with a needle. And then this is just to show when the eye becomes suddenly hard during surgery. Have you ever seen that? When it becomes suddenly hard? Yes. And if this happens during surgery, there are six causes. Two of them are outside the eye. So retrobulbar hemorrhage is one possible cause, or a very tight speculum. The speculum is too tight, and it’s pressing on the eye. And the causes that occur inside the eye — the most common one is what I just showed you. If you put fluid in the eye, you go through the zonules and hydrate the vitreous, and then you get the pressure in the eye and the iris pops out like this. So the eye goes suddenly hard, iris comes out, and usually it’s when you’ve injected fluid. And if you wait 20 minutes, it will get better. And another cause is a suprachoroidal hemorrhage. But that usually occurs once the phaco is finished. Because the eye is soft. And when the eye collapses, when it’s soft, the long posterior ciliary arteries will break sometimes, and bleed. So it’s important to try and assess which of these causes is causing the problem. And if you press the eye, and it’s moving backwards, it’s not an orbital problem. If the eye moves backwards, it’s not the orbit causing the problem. So no hemorrhage. There’s the speculum, causing the problem. And if you just change the speculum, it all gets better. Remove the speculum and replace it with an adjustable one. And this is a case where you can see that the cataract is out. The iris has come out. And the eye has gone very hard. So your first thought should be, at this stage, it’s maybe a suprachoroidal hemorrhage. And you can see the viscoelastic — the surgeon is trying to deepen the AC, but the viscoelastic is coming straight out, because the pressure inside the eye is very high. So in that case, the best course of action is just to stop. Again, the surgeon is trying to inflate the AC, but it’s very hard. Inflate. Yeah. Deepen the AC. Deepen the AC. And if it’s due to aqueous misdirection or fluid in the eye, then it will get softer, and you can put the iris back. But this is a case of what’s called capsular distension. There’s fluid in the capsule, causing a shallow AC, and if you press the lens backwards, the fluid comes out and the AC will deepen. Distension. It means inflating the bag. Distension syndrome. So the main causes outside the eye are retrobulbar hemorrhage and speculum. The main causes inside the eye are expulsive hemorrhage and capsular block. Now, this is a case of a patient who had cataract surgery, and had a retrobulbar — sorry, a suprachoroidal hemorrhage. And the surgery was stopped immediately. And this is one week later. And it’s safe to complete the surgery once the hemorrhage has stopped, a week later. Okay. So this is another type of case. This is post-trauma. This is an iridodialysis. And it’s important to move the iris out of the way before you do the cataract. So the iris is moved into position with viscoelastic, and then the iris root is sutured back with prolene sutures. That was realtime surgery. Realtime. No, not really. So once the iris is sutured back, you’ve got space to remove the cataracts. And… Put an implant in. And at the end, it all looks reasonable. This is 10-0 prolene suture, used for the peripheral user. 10-0 prolene. 10-0 prolene. And you can see some of the iris root has not been sutured, so that acts as an iridotomy or iridectomy, and lets aqueous through. So you can see that even if you look at this case at the beginning, it looks very complicated. Each step is very simple. In this traumatic cataract, the eye has been sewn up with 10-0 nylon, and you can see… A positive Seidel test. It’s still leaking. In this case, the lens capsule’s been broken, and the cataract has fluffed up. And the cataract is very soft. So it just aspirates out with a Simcoe cannula. You can use VisionBlue at any stage to stain the capsule. And now you can see the capsulorrhexis being performed. Again, everything just done very slowly, very carefully, trying to maximize your vision. And then the cataract comes out by aspiration. And at the end, the lens goes in. And the corneal suture is replaced, to try and stop the leak. And at the end, it’s not leaking. So that’s much better. That’s patients can do really well with a contact lens, because they have a fairly central scar. The vision can be poor. When you put a contact lens over that, they can improve to very good vision. Because the contact lens gives them a very regular surface, and they can overcome the effect of the scar and the astigmatism caused by the trauma. And who’s heard of Ozurdex? Anyone heard of Ozurdex? This is a steroid. And this is what it looks like. But you don’t usually put it in the lens of the eye. It’s not a good place for it. It usually goes in the vitreous cavity. This was one of our trainees, whose hands slipped when he injected it, and it went straight into the middle of the lens. And the woman complained that her vision got worse. And strangely, if you look in the textbooks, it doesn’t tell you how to remove an Ozurdex cataract. So you have to make it up. And essentially, we just did a phaco. I put an iris hook here, because that’s where the Ozurdex went in. I thought it might have damaged the zonules. The zonules. I thought it might have damaged the zonule, because that’s where the injection went in. And in fact, it came out quite easily. But the patient needed Ozurdex, and it’s expensive. So when we finished the cataract, we put the lens in, and then we did a primary posterior rhexis. And then I put the Ozurdex back into the back of the eye, where it should have been. So these implants cost several hundred pounds each. Several hundred pounds. I don’t know how many. 400, 500 pounds. And although it looks not very different at the end, it did actually sink into the vitreous cavity, and she got — it was for a vein occlusion. She got much better. Okay. So we talked about triamcinolone yesterday. I’m not going to talk too much about that. But if you suspect that there’s vitreous in the eye, always use triamcinolone. And I showed you this yesterday. You all remember the effect of triamcinolone on vitreous. Just a little bit about short eyes. If you have a hypermetropic eye, there are one or two tricks that make it easier to do the surgery. The first is that when you make the wound, the corneal wound, you keep away from the limbus, move forward into the cornea, and make it a little bit longer. Quite short, but a little bit longer than usual. And the capsulorrhexis should be done through a side port with a needle. This is just to show a diagram. It’s not very clear. But if you put your wound near to the iris root, the iris will come out, as I showed you before. If you put the wound a little more into the cornea, keep it a bit longer, then that protects the iris from coming out. And the other trick is you can bend your own needle. Instead of using a preformed cystotome, you can bend your own needle. It’s important to bend the tip at 45 degrees and then the shaft at 45 degrees, and that gives you… So here’s an example of a shallow chamber. So you can deepen the chamber with viscoelastic. And then bend the needle tip at 45 degrees and the shaft at 45 degrees. Make sure the needle is on viscoelastic. Put the needle onto the viscoelastic. And then the chamber will usually stay deep. And you usually do this before you do the main wound. This wound is too near to the limbus. Sorry. So — which bit? Say again? We can… So this is just showing, again, in the shallow chamber, the risk of the iris coming out, if the wound is too near the limbus. There it goes again. Bless you. So, again, here’s the side port being used to do the capsulotomy, and you do this before you open the eye with the main wound. Okay. Then you can open the eye, and just keep the wound a little more corneal. This one was finished with the forceps. These cross-action forceps are very nice too. They work this way. And then just a word about nanophthalmos. This is a case where the eye is less than 9 millimeters, corneal diameter. And these cause major problems. They have a very thick sclera. They get choroidal detachments and effusions. Suprachoroidal hemorrhages. Shallow ACs. And they may need a posterior vitrectomy to decompress the eye. They’re very difficult eyes. The implant is likely to be about 60 diopters. And you can buy 60-diopter implants. Some people use two lenses, but there’s not usually room for that. And the biometry is usually very inaccurate. So they often end up much less longsighted than the reading suggests. So it’s best to undercorrect them, and then do the final correction with glasses or contact lenses. And postoperatively, they can get severe iritis, choroidal effusions, aqueous misdirection, and they need careful post-op monitoring. Here’s an example of a postoperative nanophthalmic eye. Tiny cornea, very thick sclera, and lots of problems during surgery. They’re very difficult eyes to operate on. And this is 18 months later. You can see the corneal failure now. This lady’s had a vitrectomy as well, for aqueous misdirection. And her other eye was completely blind. She lost the other eye from an operation about 30 or 40 years ago. So they’re really difficult eyes. You need a very senior surgeon with experience to do them. So, in summary, it’s really important to plan these cases carefully. The difficult cases. For the shallow ACs, keep the wound a bit shorter, but move it into the cornea more. Use the needle through the side port for the rhexis, and this risk scoring is really important. Try and give appropriate cases to appropriate surgeons. Okay. So what advantages can data capture give you in performing surgery? Anybody? Anybody? Capturing data. Data capture. Information. So this is data about complications, about lenses that go in — all the data that we put in. And it’s really to make the point that if you can start to capture information about complications, then you can start to risk-stratify, as I showed you in the beginning. So the main advantage of capturing data and analyzing it is you can analyze problems and deal with them. Two strategies for shallow chambers? Are you giving them the answers? Are you giving them the answers? Are you giving the answers away? To the questions? Are you sure? So two things you can do for shallow chamber. Needle through the side port. Make the incision away from the limbus. Good. Thank you.